Scientists convert proteins into prions

COLUMBUS, Ohio, Feb. 8 (UPI) -- U.S. scientists say they have converted normal protein into a prion -- an abnormal protein that causes brain disease in humans, sheep and cows.

Ohio State University Associate Professor Jiyan Ma, senior author of the study, said prions are hypothesized to be improperly folded proteins that promote the misfolding of other proteins in a process that swiftly leads to widespread brain damage. Some investigators have challenged the prion hypothesis because it has been difficult to create an infectious prion with recombinant prion protein artificially created in bacterial cells.

Now Ma says he and his colleagues successfully used recombinant mouse protein to create prions. When injected into the brain, the prions created by the team made mice sick within 130 days. Infected brain tissue from these mice also made other mice sick, proving the prions can transmit disease.

"The major thing we showed in this study is that the infectious agent in these diseases is truly a misfolded protein," said Ma. "We folded recombinant mouse prion protein into its normal shape, then converted it into a different conformation and showed that when it infected an animal, it caused full-blown prion disease."

The study is in press in the journal Science and appeared in the journal's Jan. 20 online edition.